Make it so netns pre_exit unlinks the objects from the pernet list, so
they cannot be found anymore.
netns core issues a synchronize_rcu() before calling the exit hooks so
any the time the exit hooks run unconfirmed nf_conn entries have been
free'd or they have been committed to the hashtable.
The exit hook still tags unconfirmed entries as dying, this can
now be removed in a followup change.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
include/net/netfilter/nf_conntrack_timeout.h | 8 ------
net/netfilter/nfnetlink_cttimeout.c | 30 ++++++++++++++++++--
2 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_timeout.h b/include/net/netfilter/nf_conntrack_timeout.h
index 3ea94f6f3844..fea258983d23 100644
--- a/include/net/netfilter/nf_conntrack_timeout.h
+++ b/include/net/netfilter/nf_conntrack_timeout.h
@@ -17,14 +17,6 @@ struct nf_ct_timeout {
char data[];
};
-struct ctnl_timeout {
- struct list_head head;
- struct rcu_head rcu_head;
- refcount_t refcnt;
- char name[CTNL_TIMEOUT_NAME_MAX];
- struct nf_ct_timeout timeout;
-};
-
struct nf_conn_timeout {
struct nf_ct_timeout __rcu *timeout;
};
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index aef2547bb579..45a87eaffebe 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -33,8 +33,19 @@
static unsigned int nfct_timeout_id __read_mostly;
+struct ctnl_timeout {
+ struct list_head head;
+ struct rcu_head rcu_head;
+ refcount_t refcnt;
+ char name[CTNL_TIMEOUT_NAME_MAX];
+ struct nf_ct_timeout timeout;
+
+ struct list_head free_head;
+};
+
struct nfct_timeout_pernet {
struct list_head nfct_timeout_list;
+ struct list_head nfct_timeout_freelist;
};
MODULE_LICENSE("GPL");
@@ -575,10 +586,24 @@ static int __net_init cttimeout_net_init(struct net *net)
struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
INIT_LIST_HEAD(&pernet->nfct_timeout_list);
+ INIT_LIST_HEAD(&pernet->nfct_timeout_freelist);
return 0;
}
+static void __net_exit cttimeout_net_pre_exit(struct net *net)
+{
+ struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
+ struct ctnl_timeout *cur, *tmp;
+
+ list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
+ list_del_rcu(&cur->head);
+ list_add(&cur->free_head, &pernet->nfct_timeout_freelist);
+ }
+
+ /* core calls synchronize_rcu() after this */
+}
+
static void __net_exit cttimeout_net_exit(struct net *net)
{
struct nfct_timeout_pernet *pernet = nfct_timeout_pernet(net);
@@ -587,8 +612,8 @@ static void __net_exit cttimeout_net_exit(struct net *net)
nf_ct_unconfirmed_destroy(net);
nf_ct_untimeout(net, NULL);
- list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_list, head) {
- list_del_rcu(&cur->head);
+ list_for_each_entry_safe(cur, tmp, &pernet->nfct_timeout_freelist, head) {
+ list_del(&cur->free_head);
if (refcount_dec_and_test(&cur->refcnt))
kfree_rcu(cur, rcu_head);
@@ -597,6 +622,7 @@ static void __net_exit cttimeout_net_exit(struct net *net)
static struct pernet_operations cttimeout_ops = {
.init = cttimeout_net_init,
+ .pre_exit = cttimeout_net_pre_exit,
.exit = cttimeout_net_exit,
.id = &nfct_timeout_id,
.size = sizeof(struct nfct_timeout_pernet),
--
2.34.1
